Fabrication of porous molecularly imprinted polymer using halloysite nanotube as template for selective recognition and separation of chloramphenicol

Abstract

In this research, porous molecularly imprinted polymers (PMIPs) with thin wall were prepared using halloysite nanotube (HNT) hard template, which has a unique hollow tubular structure, for selective recognition and removal of the chloramphenicol (CAP) antibiotic frequently detected in water environment. PMIPs had the good porous structure replicated from the HNT template. The adsorption equilibrium, kinetics, selectivity and regeneration properties of CAP by PMIPs were systematically studied by static adsorption experiments. The maximum adsorption capacity of PMIPs toward CAP increased from 91.26 μmol g−1 at 25 °C to 102.5 μmol g−1 45 °C. The adsorption was in accordance with Freundlich isothermal model, indicating the multi-molecular layer adsorption. The adsorption could reach equilibrium basically within 80 min with a quick kinetic property and was confirmed by the pseudo-second-order kinetics model, indicating the chemical adsorption was rate-controlling step. The high contact temperature was beneficial to the CAP adsorption, thus which was belonged to the endothermic process. Importantly, adsorption selectivity experiments showed PMIPs had the high recognition ability for template molecule CAP whether in one- or two- component antibiotic solutions. Besides, PMIPs exhibited good thermal and chemical stability and reproducibility for practical application in further.